Suggestions on how to keep code gender-neutral

Instances of the phrases “he or she”, “his/hers”, “(s)he”, etc. All of these still exclude those who don't identify with either gender, and implicitly (slightly) favor one gender via listing it first.

“Guys” as a gender-neutral term, which has male associations. Usually in comments it implies anthropomorphism of inanimate objects and should be replaced with a more precise technical term. If it does refer to people, consider using “everyone”, “folks”, “people”, “peeps”, “y'all”, etc.

Other gendered words: “brother”, “mother”, “man”, etc.

Cases that are likely fine to leave alone include:

References to a specific person (“Rachel is on leave; update this when she is back.”).

Content in a language other than English unless you are fluent in that language.

How to change the remaining awkward intrusions of gender:

Try rewording things to not involve a pronoun at all. In many cases this makes the documentation clearer. Example: “I tell him when I am all done.” → “I tell the owner when I am all done.” This saves the reader a tiny bit of mental pointer-dereferencing.